Large volumes of fly ash and other coal combustion products (CCPs) are produced every year by coal-fired power plants. About 50% of the CCPs produced in the U.S. is buried in impoundment lagoons or dry landfills. Fly ash is generally enriched in several potentially hazardous trace elements, such as As, B, Cd, Co, Cr, Mo, Se, Sr, and V, which can leach from older, unlined disposal sites. Therefo...

On-line nuclear meters have been in use in the coal industry for many years. They have been utilised for coal quality monitoring, in the control systems for coal blending, or for separating coals in the heavy media separation process. Their operation is based on the scattering or the absorption of incident gamma radiation, and the derived density or ash value is the result of a time-averaged me...

This study investigates the feasibility of using coal fly ash and fly ash-bentonite mixtures as a barrier material for mine waste. The hydraulic conductivity of the coal fly ash was measured to be in the order of 2 x 10 -9 m/s when it was permeated with deionized water, and this value decreased significantly when the permeant was switched to acid mine drainage (AMD). Addition of bentonite to co...

The need to engineer cover systems for the successful rehabilitation or remediation of a wide variety of solid wastes is increasing. Some common applications include landfills, hazardous waste repositories, or mine tailings dams and waste rock/overburden dumps. The brown coal industry of the Latrobe Valley region of Victoria, Australia, produces significant quantities of coal ash and overburden...

Pulverized Wyoming subbituminous coal was beneficiated by low-pH oil agglomerationat CONSOL to prepare the coal for direct liquefaction. Conventional cleaning is not veryeffective in cleaning this coal; for example, conventional oil agglomeration only givesabout 20% ash rejection. To improve ash rejection, the coal-water slurry was acidifiedto a pH of about 0.5. Oil agglomeratio...

The combustion of pulverised coal in power stations results in slagging and fouling in the boiler section and this can be a more severe problem when co-fired with biomass, especially straw. Prediction of the effects of different combination of biomass and coal are helpful to the plant operators. Predictive software gives information about the onset and nature of the slag formed but often the re...

： About 500 million tons (Mt) fly ash produces from coal-fired power stations every year in China, which causes severe economic and environmental problems. In this paper, current status and prospect of fly ash utilization in China was introduced in detail. China is a huge country which has many different geographical environments and various level of economic development. So, the level and meth...

What is fly ash? Fly ash consists of the lighter particles that travel up from the coal furnaces during combustion. Bottom ash is the heavier particles that cling to the sides of the furnace and do not escape during the burning of coal. Fly ash particles range in size from 1 to 100 micrometers in diameter (EPRI, 2009) and are comprised of silica, alumina, calcium oxides and iron oxides (EPRI, 2...

Quartz (α-quartz), is the most common crystalline silica polymorph in nature and is the only polymorph found in significant concentrations in coal and coal ash. Since exposure to quartz is liable to cause lung diseases, it is very important to know its concentrations in coal ash and to evaluate its effects on the workers. Inhalation is the most effective route of entry for airborne particles of...

This paper focuses on the incremental impacts of coal ash and flue gas desulfurization (FGD) wastes associated with increased coal usage by utilities and industry under the National Energy Plan (NEP). In the paper, 1985 and 2000 are the assessment points using the baseline data taken from the Annual Environmental Analysis Report (AEAR, September 1977). In each EPA region, the potential mix of d...